docs: def set_mute(self, enable):
          """Mute or unmute the TV."""
          data = '1' if enable else '0'
          params = ('<InstanceID>0</InstanceID><Channel>Master</Channel>'
                    '<DesiredMute>{}</DesiredMute>').format(data)
          self.soap_request(URL_CONTROL_DMR, URN_RENDERING_CONTROL,
                            'SetMute', params)